Trigonometric Equations Question 377
20 metre high flag pole is fixed on a 80 metre high pillar, 50 metre away from it, on a point on the base of the pillar the flag pole makes an angle $ \alpha $ , then the value of $ \tan \alpha $ , is
[MP PET 2003]
Options:
A) $ \frac{2}{11} $
B) $ \frac{2}{21} $
C) $ \frac{21}{2} $
D) $ \frac{21}{4} $
Show Answer
Answer:
Correct Answer: B
Solution:
Let $ \angle BAC=\beta $ , $ H_1=d\tan 60^{\circ}, $ Now $ \tan (\alpha +\beta )=\frac{100}{50} $
Þ $ \frac{\tan \alpha +\tan \beta }{1-\tan \alpha \tan \beta }=2 $
Þ $ \frac{\tan \alpha +\frac{8}{5}}{1-\frac{8}{5}\tan \alpha }=2 $
$ \Rightarrow \tan \alpha =\frac{2}{21} $ .
BETA
